According to the research, intelligence is strongly influenced by the quality of the axons, the long fibres that neurons use to transmit signals; the faster the axons transmit, the faster the brain can process information. Axons are coated in a fatty sheath called myelin and the thicker it is, the faster neurons can transmit.
By comparing brain images from 23 sets of identical twins and 23 sets of fraternal twins, the researchers were able to show that myelin quality is determined by genes in many areas of the brain that play a key role in intelligence, including the parietal lobes, which are responsible for spatial reasoning, visual processing and logic, and the corpus callosum, which pulls together information from both sides of the body.
Thomson believes the research may help prevent brain diseases, such as multiple sclerosis and autism.
"The whole point of this research," Thompson said, "is to give us insight into brain diseases."
Intelligence: Nature v Nurture
